Body-acoustic device

ABSTRACT

A body-acoustic device is provided which comprises a housing (1), a diaphragm (4) dividing an inner space of the housing into a first chamber (5) and a second chamber (6), and a loudspeaker (7) mounted to an opening provided in the diaphragm, wherein the diaphragm is made of a transversely vibratory member and/or has a perimetric edge supported by an inner surface of the housing via an elastic member (10), and wherein the diaphragm (4) is further provided with a port (9) for air movement between the first and second chambers (5), (6). When the loudspeaker (7) is operated, the diaphragm vibrates with a cone paper (8) to generate sufficient heavy bass sound with high sound clarity as if the diameter of the loudspeaker had increased. The port provided in the vibrating diaphragm facilitates the vibration of the diaphragm, further increasesing the sound pressure created by the diaphragm vibration due a sound throttling effect caused by the port. As a result, sufficient and clear body-felt sound, especially heavy bass sound, can be obtained through vibration of the housing outer walls.

FIELD OF THE INVENTION

The present invention relates to a body-acoustic device wherein acousticsignals in the form of electric output from such systems as an audiosystem, arcade amusement machine, or home video game system areconverted into mechanical vibration to a human body. More particularly,the present invention relates to a body-acoustic device wherein soundpressure from a loudspeaker causes the outer walls of the loudspeaker'shousing to vibrate for transmission to a human body.

BACKGROUND ART

In general, a body-acoustic device of the above type includes a housingwherein an inner space of the housing is divided into two parts by adiaphragm having an opening for mounting a loudspeaker. When theloudspeaker is operated, sound pressure from the loudspeaker vibratesthe outer walls of the housing.

An example of such a sonic body resonator is disclosed in the JapanesePatent Application Laid-Open 2-266797. Particularly, FIG. 4 of thislaid-open application discloses a loudspeaker housing comprising a pairof dish-shaped vibrating elements joined together to form a discoid. Theinner space of this discoidal housing is divided, in its thicknessdirection, into two parts by a diaphragm made of a relatively hardmaterial such as wood, and the diaphragm has an opening for mounting aloudspeaker.

However, a problem with this type of body-acoustic device is that whenthe inner spaces of the housing are completely segregated from eachother by the diaphragm, it becomes impossible to vibrate the entireouter wall of the housing, failing to produce satisfactory body-acousticeffect.

The loudspeaker mounted to the diaphragm may be made to have a largerdiameter and a larger output for increasing vibration propagated on theoutside wall of the housing while also enhancing bass sound. However,this measure makes it necessary to increase the overall size of thehousing for accommodating the diametrically larger loudspeaker,resulting in a weight increase of the body-acoustic device and a highermanufacturing cost. Thus, the body-acoustic device becomes unsuitable asa peripheral device for a low-cost video game system.

It is, therefore, an object of the present invention to provide abody-acoustic device wherein a diametrically small speaker having asmall output can provide sufficient body vibration as well as sufficientpropagation of bass sound.

Another object of the present invention is to provide a small and lightsonic body resonator which can be manufactured at a low cost but yetcreate sufficient body-felt sound effect.

DISCLOSURE OF THE INVENTION

In order to achieve the above objects, a body-acoustic device accordingto the present invention comprises a housing, a diaphragm dividing theinner space of this housing into a first chamber and a second chamber,and a loudspeaker mounted to an opening of the diaphragm. The diaphragmmay preferably comprises a transversely vibratory member. In addition,the diaphragm may be provided with a port for allowing air movementbetween the first and second chambers.

According to a preferred embodiment, the diaphragm is supported at itsperimetric edge by an inner surface of the housing via an elasticmember. Further, the entire housing or at least a part of the housingopposite to the diaphragm, that is, a part for direct or indirectcontact with the body of a user, is made of a transversely vibratorymember.

According to a first aspect of the present invention, the diaphragm formounting the loudspeaker is a transversely vibratory member. Hence, whenthe loudspeaker is operated, the entire diaphragm vibrates together withthe vibration of the loudspeaker's cone paper, which is equivalent to anenlargement of the loudspeaker diameter. As a result, the sound pressurefrom the loudspeaker is enhanced, making it possible to obtainsufficient sound effect, especially with respect to heavy bass sound,even if the diameter of the loudspeaker itself is small.

Such a sound enhancement effect can be further intensified, as in thepreferred embodiment, by using the elastic member for mounting theperimetric edge of the diaphragm onto the inner wall of the housingembodiment because the diaphragm becomes less restrained from vibratingwith the loudspeaker's cone paper.

Further, the elastic member of the preferred embodiment placed betweenthe diaphragm perimetric edge and the housing inner wall substantiallyimproves sound clarity because direct propagation of unnecessaryvibration to the housing is restrained.

According to a second aspect of the present invention, the diaphragmdividing the inner space of the housing into the first and secondchambers is provided with a port for allowing air movement between thefirst and second chambers. Thus, transverse vibration of the diaphragmcaused by the loudspeaker is further facilitated. In addition, when thediaphragm vibrates and the air moves through the port, the soundpressure is further intensified by the so-called sound throttlingeffect, thereby effectively increasing the vibration of the housing.

As an overall result of the first and second aspects of the presentinvention, even if a diametrically small loudspeaker is used, it ispossible to generate sufficient vibration of the housing outer wallsparticularly with respect to bass sound while enhancing sound clarity.Further, it is also possible to reduce the overall size and productioncost of the sonic body resonator.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explosive perspective view of a body-acoustic deviceembodying the present invention.

FIG. 2 is a vertical sectional view of the body-acoustic device shown inFIG. 1.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will now be described in more detail withreference to the attached drawings.

A body-acoustic device according to the present invention basicallycomprises a housing 1, a diaphragm 4 which divides the inner space ofthe housing into a first chamber 5 and a second chamber 6, and aloudspeaker 7 mounted to an opening of the diaphragm 4. In theillustrated embodiment, the housing 1 is a cylinder which includes ajoined pair of housing halves 2, 3 each in the form of a bottomedcylinder made of semi-hard polypropylene. The housing halves 2, 3 areconnected to each other by a cylindrical joint 12 fitted in the housinghalves 2, 3.

Since the housing halves 2, 3 are each formed of semi-hardpolypropylene, the housing as a whole is deformable under externalforces, but the rigidity of the cylindrical side wall is increased bythe fitted cylindrical joint 12. The circular bottom or end of eachhousing half 2 or 3 is transversely deformable for vibration under soundpressure from the loudspeaker 7 to be described later.

The diaphragm 4 may be preferably made of a semi-hard, tough and readilyvibratable material such as polypropylene similar the material for thehousing 1. The diaphragm 4 is centrally provided with an opening adaptedfor mounting the loudspeaker 7 whose diameter is relatively small.

The diaphragm 4 is supported by the inner surface of the cylindricalside wall of the housing 1, that is, the inner surface of thecylindrical joint 12 in the illustrated embodiment, via an elasticmember 10. The elastic member 10 is made of a highly hermetical materialsuch as polyurethane foam or rubber and has an annular groove 11 forreceiving the perimetric edge of the diaphragm 4. The outercircumference of the elastic member is fixed, by adhesive for example,to the inner surface of the cylindrical joint 12.

Further, the diaphragm 4 is provided with a port 9 which allows air tomove between the first and second chambers 5, 6 divided by thediaphragm.

The second chamber 6 of the housing 1 accommodates a speaker drivingamplifier 13 having a frequency-halving circuit, and a connecter 14 forconnection to power supply wires.

With the above-described arrangement, when the loudspeaker 7 isoperated, the diaphragm 4 itself can vibrate with the cone paper 8 ofthe loudspeaker 7 because the diaphragm 4 carrying the loudspeaker 7 istransversely deformable and because the perimetric edge of the diaphragma is supported via the elastic member 10 by the inner wall of thehousing 1. This means that even the diameterically small loudspeaker 7can provide a sufficient sound pressure effect which is equivalent tothat obtainable when the diameter of the loudspeaker 7 is increased.Particularly, the diametrically small loudspeaker 7 can generatesufficient heavy bass sound with remarkably improved sound clarity.

Further, the port 9 provided in the diaphragm for establishingcommunication between the first and second chambers 5, 6 furtherenhances the vibration of the diaphragm 4 with the cone paper 8 when theloudspeaker 7 is driven. At the same time, upon vibration of thediaphragm 4, the port 9 provides a sound throttling effect whichincreases the sound pressure. These factors contribute to intensifyingthe vibration on the outer walls of the housing, namely the respectiveend walls of the housing halves 2, 3. As a result, when the loudspeaker7 is operated with the housing 1 held in contact with the user's body,the user can sufficiently feel the sound, particularly heavy bass sound,with outstanding sound clarity through body stimulation.

In this way, the sonic body resonator according to the present inventioncan provide satisfactory and excellent body-felt sound even if use ismade of a diametrically small loudspeaker, thereby enabling a pricereduction and a compact design.

Further, since the housing 1 of the illustrated embodiment is formed ofsemi-hard polypropylene which has both toughness and flexibility, thehousing can transmit the speaker sound to the human body at a highfidelity and clarity while being readily adaptable to the human body butyet providing sufficient strength and durability for heavy-duty use.Furthermore, polypropylene as a material for the housing 1 has a numberof advantages such as ease in blow forming, considerablly lowmanufacturing cost, and light weight, all contributing further to theweight and cost reduction in the body-acoustic device according to thepresent invention.

The scope of the present invention is not limited to the embodimentdescribed hereinabove, and all design modifications to be made under thespirit set forth in the appended claims are included within the scope ofthe present invention. For example, the diaphragm 4 may be made not onlyof semi-hard synthetic resin but also of a cardboard or the like.Although it is preferable that the diaphragm 4 have a certain degree offlexibility for transverse deformation, the diaphragm may have a certaindegree of rigidity if the perimetric edge of the diaphragm 4 issupported by the inner surface of the housing via the elastic member 10.

Conversely, if the diaphragm 4 is flexible for enabling transversevibration, substantially the same effect as described above can beexpected even if the diaphragm perimetric edge is connected to thehousing inner surface without using the elastic member 10.

Finally, experiments have revealed that, for better sound effect, theport 9 in the diaphragm 4 should be brought away from the loudspeaker 7to be located as close to the outer edge of the diaphragm as possible,and such a port should be provided only at one position rather than at aplurality of positions.

We claim:
 1. A body-acoustic device comprising a housing, a diaphragmhaving an opening and dividing an inner space of the housing into afirst chamber and a second chamber, and a loudspeaker mounted to theopening of the diaphragm,wherein the diaphragm is made of a traverselyvibratory member, the diaphragm being provided with a port for allowingair movement between the first and second chambers, and wherein thehousing has no sound outlet opening so that the housing is substantiallyclosed.
 2. The body-acoustic device according to claim 1, wherein thediaphragm has a perimetric edge supported by an inner surface of thehousing via an elastic member.
 3. A body-acoustic device comprising ahousing, a diaphragm having an opening and dividing an inner space ofthe housing into a first chamber and a second chamber, and a loudspeakermounted to the opening of the diaphragm,wherein the diaphragm isprovided with a port for allowing air movement between the first andsecond chambers, the diaphragm having a perimetric edge supported by aninner surface of the housing via an elastic member, and wherein thehousing has no sound outlet opening such that the housing issubstantially closed.
 4. The body-acoustic device according to claim 3,wherein at least part of the housing opposed to the diaphragm is made ofa transversely vibratory member.